The invention relates to a yarn processing device fitted with a preferably separable screw connection of two processing elements made of highly wear-resistant material, especially ceramics, and the use thereof.
The processing of filament yarn has to achieve essentially two tasks. On the one hand the yarn made of industrially produced filaments is to be given a textile character and textile engineering properties. On the other, the yarn is processed with a view to specific quality features required for further processing and/or for the final product in some cases yarn qualities will be required which are not necessary with products made of natural fibers andxe2x80x94what is morexe2x80x94these cannot even be realized. The fields of application are within the industrial processing of textiles e.g. for the construction sector, automotive production but also for the manufacture of carpets and for specific textile products the sports and leisure industry offers. Moreover, spun yarn is to be treated by certain preparations to facilitate an optimal industrial processing, and the processing procedure for yarns and surface formations is to be optimized. Optimization in this context includes preservation and improvement of certain quality criteria and reduction of production costs which is to include downtimes during the entire span of processing.
Within the framework of the spinning of filaments various treatments such as the preparation and the finishing of yarns by way of yarn processing spinnerets are important stages. The structural change of turning smooth yarns into a textured or interlacing yarn is achieved by mechanical aerodynamic forces. In the former case a flow of air in the supersonic range, in the latter a dual turbulent flow is generated. Air processing spinnerets are utilized to improve the yarn structure. The improvement of quality by means of superheated steam, e.g. the relaxation during the stretch process or after another preceding procedural intervention is a very demanding process.
In all cases, the spinneret elements are produced from a highly wear-resistant material, because their service life would otherwise be too short. The main source of problems for the yarn processing spinnerets lies in the preparation. During preparation, or lubrication, the yarn is fitted with protective substances immediately after the spinning process and/or the production of the individual filaments. These protective substances are intended to be an aid for subsequent processing. The substances used for the preparation provide an oily sliding property which provide the yarn with a lowest possible sliding friction during all the processing steps, reduces the risk of damaging or rupturing the yarn and limits to a minimum the abrasion arising at the sliding surfaces of the transportation and processing devices. There are many other factors which are favorably influenced by the preparation and/or the preparation means such as electric charges. Another field to be mentioned in this respect is the protection against a fungus attack of the yarn during storage between the various processing steps. The factors mentioned offer an impressive idea of the practical environment for the yarn processing elements. The interaction of pressure, heat, moisture, and a variety of chemical substances during the preparation causes very aggressive conditions for the material of the yarn processing spinnerets, above all, however, for any connection means utilized on the spinnerets. The new solution is focused above all on the class of separated and specifically two-piece yarn processing spinnerets with which preferably each part has recesses be it for the yarn canal and/or a processing chamber. When assembled the parts should fit exactly. Moreover, lateral sliding movements of the yarn run should be avoided to facilitate an exact positioning.
The invention is based on the task to develop yarn processing spinnerets and/or yarn processing elements which have a maximum of wear-resistance as regards the preparation and which facilitate a long service life. A special portion of the task was to create a spinneret connection for separated yarn processing element which facilitates a swift and precise positioning and can be used for highly wear-resistant materials such as ceramics including for thermal treatments.
The solution proposed in accordance with the invention is characterized in that the connection of the separated spinnerets presents at least one dowel pin which is contained in at least one part of the element by means of mechanical clamping devices or holding devices and lead in a second part through a corresponding bore for the purpose of positioning and assembly/disassembly of the dowel pin connection in axial direction.
The inventors have discovered that a spinneret with a connection device remains safe to operate only if the spinneret can resist to pressure, heat, steam, or chemical substances. The hitherto known adhesive connections did not represent a satisfactory solution to all problems encountered in practical operations. What is more, a study of an adhesive connection can only be made insofar as practical conditions are actually known at present. However, the composition of an adhesive connection cannot be determined with a view to the exposure to chemical substances unknown today but possibly employed in the future. At best, a statement can be made with respect to exposure to an increased heat or moisture. Preferably, with the new solution, the connection devices are arranged in a common orientation, preferably aligned with the yarn run. Surprisingly it was established that with a corresponding pin connectionxe2x80x94as compared with the state of the artxe2x80x94it is possible to substantially reduce the size of the entire spinneret element and have them built quasi in a miniaturized form. Specifically if a dual spinneret is used or if several spinnerets are arranged in parallel, the separation between two adjacent yarn runs can be essentially smaller than before; in some applications this even had repercussions on the size of the galette. Owing to the new connection, the possible miniaturization allows the implementation of additional yarn runs for each individual machine size, and, correspondingly, an increase of the overall performance of the machine. This means that the connection device as an assembly/disassembly aidxe2x80x94otherwise rather known from the watch and clock engineeringxe2x80x94and the line-shaped application offers unexpected advantages. The frictional connection of the elements can be ensuredxe2x80x94just as with the state of the artxe2x80x94by means of a classical screw connection. Specifically when used as an interlacing spinneret and as a thermal treatment element and alsoxe2x80x94this will yet be shownxe2x80x94as a migration spinneret, the new solution is very advantageous.
The invention comes with a variety of especially advantageous designs. In this respect, reference is made to claims 2 through 12. In accordance with one specifically preferred solution, two dowel pins are used with two parts to be joined. For this purpose, two essentially identical alignment bores are fitted on the one hand, and one alignment bore and one slot alignment bore on the other. It is taken into account, that the highly wear-resistant materialsxe2x80x94above all ceramicsxe2x80x94are not only very difficult to process, but also present a different dilatation under temperature changes as compared to metal products. The clamping device or the holding device for the dowel pins can be either a tension spring or an open straining ring. For this purpose it is proposed to fit the dowel pins with a groove for one corresponding straining ring each so that the straining ring""s diameter can be reduced during assembly and disassembly of the dowel pins by means of an external dynamic effect. Instead of using a tension spring it is also possible to provide one section of the pins joltable e.g. by different solidity so that a mechanical jolt can be used instead of a tension spring within a bore increase. Preferably the dowel pins are miniaturized in their diameter, and/or provided in a needle-shape. Primarily, the dowel pin has a positioning function. For the positioning, the dowel pin""s dimension must only be sufficiently strong so that the pin cannot be damaged during the assembly of the parts, since during the yarn processing there is barely any force exerted on the pins. The frictional connection is preferably provided by means of a screw connection. In accordance with another embodiment an entering cone for longitudinal positioning is fitted on the spinneret element with which the dowel pin is held with the clamping devices. The cone leads over to an after-body and/or a bore increase for the clamping device and/or a straining ring as a holding shoulder. The new solution is perfectly suited when it comes to periodic cleaning which is often carried out by means of ultrasound.
In the two-piece design the processing element is provided as a spinneret plate and a cover plate whereby the dowel pins can be fixed in the spinneret plate preferably rotatable by means of the clamping device. For this purpose the cover plate is fitted with a pocket bore or a through bore with a slightly enlarged diameter at the end of the bore and an alignment bore for the dowel pin in the insertion bore part. It is specifically preferred to have the connection provided with two dowel pins which even when assembled have a very small play inside the alignment bore so that the dowel pins remain rotatable at least theoretically. Moreover it is possible to arrange the dowel pins slightly protruding from one side of a spinneret element so that the spinneret element can be plugged into a base plate like LEGO blocks in any preferred number. The use of two dowel pins has the tremendous advantage that as regards the positioning the connection is geometrically accurate or within a narrow tolerance range. If only one dowel pin is used this result can be obtained if the screw connection itself is fitted with an aligning shoulder. If more than two dowel pins are used this can cause disadvantages related to the problems of dilatation and accuracy in production. This means that with extreme thermal strain, two dowel pins are deliberately preferred. If there is no or only a moderate thermal strain two or more dowel pins can be utilized. In the huge majority of applications at least one spinneret part, preferably, however, both spinneret parts is/are made of a ceramic material and the dowel pins are made of high-tensile steel or ceramics. The invention also relates to the utilization of the yarn processing device. Insofar reference is made to claims 13 and 14. If mechanical clamping devices are envisaged for the pins on both sides, the clamping effect on one side shall be markedly smaller than on the other so that the pin will remain in a defined part.